static int i2c_imx_probe()

in busses/i2c-imx.c [1405:1535]

• 97 lines of code
• 12 McCabe index (conditional complexity)

static int i2c_imx_probe(struct platform_device *pdev)
{
	struct imx_i2c_struct *i2c_imx;
	struct resource *res;
	struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
	void __iomem *base;
	int irq, ret;
	dma_addr_t phy_addr;
	const struct imx_i2c_hwdata *match;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	phy_addr = (dma_addr_t)res->start;
	i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL);
	if (!i2c_imx)
		return -ENOMEM;

	spin_lock_init(&i2c_imx->slave_lock);
	hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	i2c_imx->slave_timer.function = i2c_imx_slave_timeout;

	match = device_get_match_data(&pdev->dev);
	if (match)
		i2c_imx->hwdata = match;
	else
		i2c_imx->hwdata = (struct imx_i2c_hwdata *)
				platform_get_device_id(pdev)->driver_data;

	/* Setup i2c_imx driver structure */
	strscpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
	i2c_imx->adapter.owner		= THIS_MODULE;
	i2c_imx->adapter.algo		= &i2c_imx_algo;
	i2c_imx->adapter.dev.parent	= &pdev->dev;
	i2c_imx->adapter.nr		= pdev->id;
	i2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
	i2c_imx->base			= base;
	ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev));

	/* Get I2C clock */
	i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(i2c_imx->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk),
				     "can't get I2C clock\n");

	ret = clk_prepare_enable(i2c_imx->clk);
	if (ret) {
		dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
		return ret;
	}

	/* Init queue */
	init_waitqueue_head(&i2c_imx->queue);

	/* Set up adapter data */
	i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);

	/* Set up platform driver data */
	platform_set_drvdata(pdev, i2c_imx);

	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	ret = pm_runtime_get_sync(&pdev->dev);
	if (ret < 0)
		goto rpm_disable;

	/* Request IRQ */
	ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED,
				   pdev->name, i2c_imx);
	if (ret) {
		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
		goto rpm_disable;
	}

	/* Set up clock divider */
	i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
	ret = of_property_read_u32(pdev->dev.of_node,
				   "clock-frequency", &i2c_imx->bitrate);
	if (ret < 0 && pdata && pdata->bitrate)
		i2c_imx->bitrate = pdata->bitrate;
	i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
	clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
	i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));

	i2c_imx_reset_regs(i2c_imx);

	/* Init optional bus recovery function */
	ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
	/* Give it another chance if pinctrl used is not ready yet */
	if (ret == -EPROBE_DEFER)
		goto clk_notifier_unregister;

	/* Add I2C adapter */
	ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
	if (ret < 0)
		goto clk_notifier_unregister;

	pm_runtime_mark_last_busy(&pdev->dev);
	pm_runtime_put_autosuspend(&pdev->dev);

	dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
	dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
	dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
		i2c_imx->adapter.name);
	dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");

	/* Init DMA config if supported */
	i2c_imx_dma_request(i2c_imx, phy_addr);

	return 0;   /* Return OK */

clk_notifier_unregister:
	clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
	free_irq(irq, i2c_imx);
rpm_disable:
	pm_runtime_put_noidle(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pm_runtime_set_suspended(&pdev->dev);
	pm_runtime_dont_use_autosuspend(&pdev->dev);
	clk_disable_unprepare(i2c_imx->clk);
	return ret;
}